Battery testing and charging apparatus



Patented Feb. 6, 1951 BATTERY TESTING. AND

QHAEQINQ Robert. H. Riley, Jr., and Thomas. w. Holland, Towson, Md., assignors to TheBlack & Decker Manufa C p y, 11 mm Md a G9!- poration of Maryland li pplication Qctqber 12, 19.46, Serial No. 702,936

01 ima -329 19.)

' This invention relates generally to servicing apparatus for automobile storage batteries. 7 More. articularlyit has reference to "the electrical cirand controls concerned with the testing, desulphation, and quick charging of batteries. u The primary object of the invention is to provide simplification and iiicreased"reliability in charging apparatus by provi'di'ng improved means whereby abatter'y to be serviced may first be tested and. when requird pre'pared for charging'by quick dischargeand desulphation. A further object of the invention is to provide testing" and discharge" circuits which may be. used separately and distiiictlyfromthe charging circuit, yet WhiCH in cita'in phases cooperate. vvith the latter. Another object is to provide in the servicing apparatus an auxiliaryAQ-Qeircuit which may be used in direct eonjunctidri 'withthe"di"sclia'rge' circuit as more fully described below. A still 'further object is to" provide a system of battery discharging ,testing and charging circuits which"may be controlled by 'a single m n-nar operable means so arranged as to prevent'rnis takes in circuit book 1115; H

f To. accomplish these and related objects, there are 'providedcertain improved structural details and circuit arrangements as"a're 'diagrarnmatif (Sally illustrated in then pmp drawing wherein: i

s Fig. l is a diagrammatic outline of key StIllC-r ture. and pertinent electrical ci'cuitsin thepreferired form ofthe iriventionfand Fig. 2 is a diagrammatic outline ofa modification or the invention including an additional, sensitive, secondary control circuit; Fig. "3" is a mechanical diagram'ofan error preventing manual control and selecting? switch means for setting the circuits of theapp'ar' us; a .x; ...u'..' .m Fig 4 is a iragmentary plan view of part of a panelas ociated with'th'e manual controlme'ans sho'wn'in Figfs.

i fifore' referring to the drawings in detail, it maybe well to state 'thatthe structure afiacn cuit shown and described are, of course, housed suitable; enclosedease; mo nte en whens so hat it'cancoiiveniehtlybejrnovedabout. scan a Housing fs'dfthe' 'fioiiiial' for battery servieing, having a panerana" selector controls, iii'dicaitoilight'andtliefl'ik r "Sinceftlie mvemien resides primarily in the internal: arrangement "1 t seirvicing circuits, littl'furtherne'ed b' s d n6 c th ch e 2- For the. sake, of clarity the component parts of.-. the, apparatus can best be described. in the, circuits in which, they are used. In Fig. 1, as a part ottheprimary A.-C. circuit, is a source. of alternating current, II having. a

main line switch and'circuit breaker. L2; and a timer-switch mechanism I3. A'motor and fan' II; are provided for coolinglthe entire servicing. ape pai'atus. Connected with: the timeris a panel and signal. light used in. conjunction with dis-i charging and charging. When the, timer is. in.

current circuitthere is a secondary transformer,

, winding ZflIwith its rectifier 2| and negative line 22- running to the battery'23 with, its return line;

24, connected in which is a shunt arnmeter 2,5;

A voltmeter 26 is provided across the. battery. terminals so that the'condition of the batterymay beascertained. There is another secondary. circuit, which, we have designated a test-discharge circuit to'be used for an initial determina; tionofthe condition of the. battery. In this cir; cuit 3l,"'which shares certain'lines in common with thebatte'ry charging circuit above described, there is a'discharge resistor element 32 and ter-: minals 33 and '34 of'a solenoid switch having a contact bar 35 on the solenoid armature. Th solenoid armature may be moved to bring bar 35 into contact with these terminals against the action of av spring 46 by manually moving control knob l9 and its connecting rod 3-1 to. point 41$- andthen depressing the knob against spring a 36. When this test discharge circuit 3i is closed momentarily," a reading of thevoltmeter 26 willv determine'the condition of the battery;

'W-hena sulphat'ed condition is indicated a quick discharge is given thebattery. In bringing about thisduick 'discharge'two circuits are employed; First, circuitbreaker or? main line switch l2 is closed and timerswitch l3 isset to an"on posi month-en control knob l9 manually moved to contac' int 40 which closes auxiliary A'.-'C."cir,-; cuit 4! o energize" a"relay"coil 42 operating-a switch 4 3' 'forffclc'ising' discharge control circuit. '44 59 in th sco'lidary. This cont'rbl circuit l linclu'des tact bar 35. closed against the action of spring 46. When this occurs, discharge circuit 3| will automatically open. In addition to closing the auxiliary A.-C. circuit 4| and the control circuit 44 as described above, control knob l9 must be manually depressed in order that contact bar 35 will be positioned against terminals 33 and 34, thereby closing the discharge circuit as described below. When both these preliminary requirements have been made, the magnetism in the relay coil 45 will hold contact bar 35 against the terminals 33 and 34, thereby holding the discharge circuit closed until such time as the battery potential is reduced to the predetermined minimum and thus weakening the, action of said relay coil 45 and allowing the action of spring 46 to open the discharge circuit. It should be clear from the foregoinglthat while the action of this discharge circuit is initiated by the manual depression of control knob H! as one of the requirements for discharge, the control knob I9 need not be held down because the control circuit 44 will maintain the closure of the discharge circuit by the magnetism of relay coil 45 after contact bar 35 has once been placed against the terminals 33 and 34. It will be noted that switches 333435 can be closed manually at two different positions 4'! and 4|! of tap switch |8, but it must be held closed manually inthe first instance and is held closed by A.-C.

circuit dominance in the second instance. When this switch is manually closed by depression of the I control knob l9 at position 41 none of the secondary circuits, except the testrdischarge circuit, functions.

An alternative form of hook-up for auxiliary A.-C. circuit 4| is indicated bythe dotted connection 64 in Figs. 1 and 2. In this form the auxiliary A.-C. circuit 4| is connected into the pri-- mary A.-C. circuit to the left of the timer at 65. This arrangement permits activation of the auxiliary A.-C. circuit 4| and discharge control circuit 44 (54 in Fig. 2) Without thenecessity of traverse through the timer |3.. In this form discharge can be effected by closure of .main line switch l2; together with the required depression of control knob 9 and movement of the tap switch to contact point 40. Since .it is'important that fan motor 4 be on when discharge is taking place, in this alternate form the fan motor will also be connected to point 65 is indicated by the dotted an additional sensitive secondary control circuit has been provided. Connected with the primary 4 cuit 3|. It is intended that relay coil 55 will act as a more sensitive circuit breaker for certain types of battery servicing than will the standard, less sensitive relay coil 45.

In Figs. 3 and 4 we have shown a mechanical representation, in a more or less diagrammatical manner, of the elements comprising the single knob operating means for setting the primary side of the transformer and for setting the secondary circuits. The mechanism is such that the solenoid "switch cannot be closed except at the positions 40 and 41. This mechanism is supported by, and associated with, an inner structural panel 50, and

now will be described. 15

shaft 31 is fork-shaped with the legs of the fork :formation disposed in slots formed in a disk 5| secured to one end of a switch-shaft 62. One leg 58 of the fork is longer than the other and is adapted to prevent depression of the knob 9 and its shaft 31 except when the leg 58 registers with either of two openings 40 or 41 formed in the panel 50. A third leg 59 of the fork formation is adapted to project through an opening in panel 56 and depress the solenoid armature of solenoid mechanism 45 against the force of the armature spring 46, which tends to maintain the solenoid switch 33-3534 normally open. Since the position of the solenoid 45 is fixed, two legs 59 are provided and spaced to conform with 404l. The solenoid mechanism may be supported on the panel 5|] by any suitable bracket means, not.

, outward, as shown in Fig. 3. The tap switch mechanism for the primary coils and the contacts 40-41 may be combined in an insulated contact barrel 6!] which is rigidly supported by a -bracket6| secured to panel 50. The contact barrel may also constitute a bearing for the "switch shaft 62.

The switch shaft may carry an insulated contact sleeve 63, of which the switch arm I8 is an integral part. A suitably mounted fiat spring brush 6! comprises the connection 0 the A.-C. line H to the switch arm I8.

Proceeding now to the operation of our battery servicing apparatus, battery 23 should first be connected up in the normal fashion. Then the battery may be tested by the manual depression of the control knob IS, with the tap switch I8 discharge control circuit, which in the modification is given the referencenumeral 54, is an all- I.

ditional control circuit 51. When primary con-- trol circuit 54 is closed by the action of the relay 42 and switch 43 as above described, relay coil in sensitive, secondary control circuit 51 will effectv closure of the primary discharge control circuit through switch 56 when: control knob I9 is depressed. This additional secondary control circuit 51 is connectedfrom the side of the primary 1 control circuit 54 to -the other side at contact 33 and thus acts as asensitive circuit-breaker and circuit opening means since, when the battery 7 :opening of the primary, control circuit 54, relay -.c,oil 45. will be deeiig giz ed .and. spring 45- will. lift contact 'bar 35, thus openingthe"discharge'cir and fork leg 58 at position 41 andthecondition of the battery determined by a reading of the voltmeter 26. Before proceeding, to the discharging of the battery for desulphation when necessary, ins

preparation for subsequent charging, primary 'A.-C. circuit II will be closed by the activation, j

The fan, signal light and iary A.C, circuit 4| as=indicated by the dottedE/ lines 64 and described above, provision is made for; 1

activation of this circuit for discharge purposes without employment of the timer relay 3 merely by closing main line switch I2.

Reviewing in functional terms wh'at has been;

indicated above in thebrief description asto dis ,clisirging, control knob |9' .w i1l first-bemanually. -.;moved to contact point "46,thereb'y clo'siiig'tii auxiliary A.-C. circuit 4| which, in turn, will 'efiect'closure of the primary control circuit 44 of Fig. 1 by action of the relay coil 42 and -the consequent closing of switch 43. Together with the moving of control knob I9 to contactpoint 40, control knob l9 must be manually depressed, thereby moving connecting rod 31 against the action of spring 36 to place contact bar 35 across the terminals 33 and 34. Closing of the primary control circuit 44 and the discharge circuit 3! by -contact bar 35 establishes a circuit from the battery 23 through discharge resistor 32. The battery current through the primary control cir- "c'uit will energize relay coil 45, thereby maintaining-automatic closure of contact bar 35 when control knob I9 is released. When the battery voltage drops, due to discharge, to some desired and predetermined value, current through the primary control circuit will be sufficient to keep relay coil 45 energized to a degree which will maintain closure of contact bar 35. against the terminals 33 and 34 in opposition as: the action of spring 46. When this occurs, action of spring 45 will open the discharge circuit.

In the modified form shown in Fig. 2, the same procedure for discharge must be followed, but here, when the auxiliary A.-C. circuit is closed to eifect closure of switch 43 and primary control circuit 54, the current througli' the second- 'ary control circuit 51 will energize relay coil 55,

closing switch 56 (normally open) and control circuit 54 which energizes relay coil 45 in discharge-circuit 3| and holds contact bar 35 closed when control knob I9 is released; When the battery voltage across discharge resistor. has dropped, due to discharge, to a predetermined value, sensitive relay coil 55 willfthen have insuilicient energy to maintain switch 56 in a closed position and hence the primary control circuit 54 =will be opened, thereby breaking the holding action oi'relay coil 45 and allowing 'contact bar 35 toopen and break the dischargei'circuit.

It will also be apparentthatdischarge may be terminated prior to the time the'predeter- 'in'ined discharge condition would normally be ,reached in the control and discharge circuits through the action of discharg'resistor 32 by other means. If control knob tS-is moved from contact position 40 the auxiliary A.-C. circuit 4! will be open. deenergizing relay coil 42 and opening switch 43, thereby in turn deenergizing relay coil 55 and opening the: primary control circuit 54 at switch 56, with the obvious effect upon relay coil 45 and contact 35. This mode of termination also applies to the hook-up in 1 through circuit 44. 1 9

=: :1 Once-the battery to be-servicedhas been tested and discharged for desulphation; when required, to a desired point, it will thenb'e in a condition for charging. By use of movable tap switch [8, the initial charging rate to be given the battery may be selected by positioningn'control knob 19 against any one of the selector positions Ila, I'Ib, llc, 11d and I'If. The various selectable positions I! represent various number of turns in the transformer primary l6.' -The low voltage alternating current from the- -ftransformer--:secondary 20 is converted to direct current by the rectifier 2| and connected to the terminals of the battery 23. Voltmeter 26 is, also connected to theterminals of the battery. Shunt 'ammeter 25, provided in the line 24 of theqbattery charging circuit, indicates the charging current.

er mechanism and the signal light can be indicate the end of a discharge period as well as to indicate the end of a charging period When this is done the auxiliary A.-C. circuit will be open and also the light circuit l5 will be open until the timer is turned to an on position. The timer can be turned to:an on position corresponding to, say five minutes, and then the operator can tell when the discharge is discontinued as the light will be out-asi'soon as the fiveminutes are up. Generally thesolenoid will have'opened in a shorter time due to the voltage in coil 45 being decreased, but in case the coil did not drop it out the timer would in a short enough time so'that there would be no damage to-the battery. The operator can always make a check by the voltmeter to determine whether the battery was sumciently discharged. This arrangement makes it possible for the operator to be doing something else and not have to stand and watch the machine. Through the mechanical lock out arrangement disclosed the: control knob I 9 can'be depressed only when it is turned to contact positions 40 and 41 on tap switch [8.

By having the manually operated tap switch", [8 and control knob l9 coordinated in the manner described and the auxiliary A.-C. circuit 4| arranged as indicated by the dot and dash lines, the apparatus cannot be misused, for at no time can the primary side of the transformer be energized while the testing and-discharging circuits are being used,- since the timer switch will be open in this instance.

Although we have described butone form of the invention, it is understood that other forms might be adopted, all falling within the scope of the claims, as follows. a,

We claim: I

1'. In an apparatus for servicing storage batteries, a primary A. C. circuit including a tapped primary Winding of a transformer; a battery charging circuit including the secondary of the transformer and a rectifier; a selector control switch in the-A. iC.-ci1"cuit for varying" the windings'us'ed-"in the primary of the transformer, said selector switch having for battery test and discharge purposes two selector positions whereat the switch is neutral with respect to the primary windings; a normally open battery test and discharge circuit connected across the output of the battery charging circuit; a discharge resistance in the discharge circuit; a switch in said discharge circuit, said switch being biased open "and being manually operated to close said discharge circuit, there being means extending between said switch and the selector control switch to permit closure of the discharge circuit switch atthe neutral-positions of the selector control switch-for battery test and discharge purposes; an auxiliary A.{ Cf c rcuit closed by the selector control switch at the battery dischargaposition of; said selector control switch; a relay coil in the auxiliary A. C. circuit; a discharge control circuit connected'directly in parallel with the discharge resistance, said discharge control circuit including aswitch closed by the relay coil inthe auxiliary A; Q circuit, solenoid in series with the A. C. energized switch,'-said solenoid being associated with the manually operated discharge switch to hold it closed against its normal opening bias and being adapted to release the discharge switch when the battery potential drops below a level predetermined by the opening bias of the discharge switch.

2. In an apparatus for servicing storage batteries, a primary AQC. circuit including a tapped at-corms 7: primary winding of a transformer; a battery charging circuit including the secondary of the transformer and a rectifier; a selector control switch in the A. C. circuit for varying the windings used in the primary *of the transformer, "said selector switch having for battery test and discharge purposes twoselector positions whereat the switch. is neutral with respect to the primary windings; a normally-open battery test and discharge circuit connected across the output of the battery charging :circuit; a discharge resistance in the'discharge circuit; a switch in said discharge circuit, said switch being biased open and being manual-ly bperated to close said discharge circuit, there being means extending'between said switch and the selector control switch to permit closure of the discharge circuit switch. at the neutral positions of the selector control switch for battery test-and discharge purposes; an aux "iliary A. C. circuit closed by the selector control switch at the battery discharge position of said selector control switch; a relay coil in the aux"- iliary A. C. circuit; a primary discharge control circuit including a switch closed by the relay coil in the auxiliary A. C. circuit, a sensitive switch directly in series with the A. C. energized switch, a solenoid associated with the manually operated discharge switch to hold said discharge switch closed against its normal opening bias, said iprimary control circuit being connected across the battery-charging circuit with the control circuit leg from the sensitive switch connecti-ng at the same side of the battery charging circuit to which the discharge switch is connected;

a sensitive auxiliary discharge control circuit comprising a relay coil for closing the sensitive switch, said relay coil being connected from a .point common to the twoswitches inthe primary controlcircuitto a point in the discharge circuit between the discharge resistance and the dis.- charge switch.

3. In anapparatus for servicing storagebatteries, a primary A. G. circuit including a tapped primary winding of a transformer; a timer switch controlling the A. C. input; a battery charging circuit including the secondary transformer and a rectifier; a selector control switch in the A. C. circuit for varying the windings used in the primary of the transformer, said selector switch having for battery test and discharge purposes two selector positions whereat the switch is neutral with respect. to the primary windings; a normally open battery test and discharge :cir- ,cuit connected across. the output of the battery charging circuit; a discharge resistance in the discharge circuit; a switch in said discharge Gil? cuitsaid switch being biased open and being manually' operated to. close said discharge circuit, there, being .means extending between said switchand. the selector control switch to permit closure of the discharge circuit switch at the neutral positions of the selector control switch ,for battery. test and discharge purposes; an auxil'i'ary A. C. circuit closed by the selector control switch at the battery discharge position of said selector controlswitch; a relay coil in the aux: iliary A,v C. circuit; a primary discharge control 8. circuit including a switch closed by the relay coil in the auxiliary A. 'C. circuit, a sensitive switch directly in series with the A. G. energized switch, a solenoid to hold the manually operated dischargeswitch closed against its normal opening bias, said primary control circuit being connected across the battery charging circuit with that control circuit leg from the sensitive switch connecting at the same side of the battery charging circuit to which the discharge switch is connected; a sensitive auxiliary discharge control circuit comprising a relay coil for closing the sensitive switch, said relay coil being connected from a point common to the two switches in'the primary control circuit to a point in the discharge circuit between the discharge resistance and the discharge switch, and being adapted to release the sensitive control switch when the battery potential drops to aipredetcr mined value. p

v 4. In an apparatus for servicing storage bat"- teries, a primary A. C. circuit including a tapped primary winding of a transformer; a battery charging circuit including the secondary of the transformer and a rectifier; a selector control switch in the A. C. circuit for varying the wind;- ings-used in the primary of the transformer,said selector switch having for battery test and discharge purposes two selector positions whereat the switch is neutral with respect to the primary windings; a normally open battery test and discharge circuit connected across the output of the battery charging circuit; a discharge resistance in the discharge circuit; a switch in said discharge circuit, said switch being biased openand being manually operated to close said discharge circuit, there being means extending between said switch and the selector control switch to. permit closure of the discharge circuit switch at the neutral positions of the selector control switch 'forgbattery test and discharge purposes; an auxiliary A. C. circuit closed by the selector control switch at the battery discharge position of said selector control switch; a relay coil in the auxiliary A. C. circuit; a discharge control circuit connected directly in parallel with the discharge resistance, said discharge control circuit including a switch closed by the relay coil in the aux iliary A. C. circuit and a solenoid of a solenoid operated means for holding the manually operated discharge switch closed against its normal opening bias.

ROBERT H. RILEY, 5'11.-

THOMAS W. HOLLAND.

REFERENCES CITED The following references are of record in the 

